The present invention relates to a ball point pen writing instrument, and more particularly to a ball point pen writing instrument simply using common aqueous ink as its writing medium.
Although the conventional ball point pen has the advantages of convenience, handy, inexpensive etc. however, it still has several disadvantages in practical application such as, easy leaking, frequent build-up of a mass of ink at the pen point during writing, making the written words very hard to identify, and staining on paper and on arms by the ink; frequently a phenomenon of non-continuous flow of ink during writing in Winter time; the words written with it become easy to diffuse and blur after a period of time so that important documents may not be kept for long periods of time.
In view of these disadvantages of conventional ball point pens mentioned above, all the important documents or matters of great concern rely on the fountain pens as writing instruments, because the words written with a fountain pen are clear, remain unblurred, and are not hampered by discontinuous ink flow. However, there are still disadvantages such as, inability to write in any optional direction, pen point easy to split and difficult to duplicate, the sharpness of the pen point causes damage to the writing paper, the capillary ink volume from the pen point not always in the ideal conditions when writing in some soft papers easy to diffuse, and its high cost for making pen point and not long lasting.
On the market are various writing instruments, including signature pens using rolling ball as writing pen point such as, "Sheaffer", "Ball Pentel", etc. As these instruments possess the advantages of both ball point pens and fountain pens to a certain extent, which is capable to fulfill the requirements of the market demand, they have become the favorites of the market of writing instrument for quite some time. The space behind the ink guiding fibers, which can achieve the writing purpose by means of a special quick-drying semi-oily ink with good osmotic property, is conveyed by said core rod with its capillary tube effect. After the ink is exhausted the general users cannot refill by themselves, and/or if the cap is not closed tightly or the pen is laid down for a longer time, the writing medium will be dried out. If the semi-oily ink is switched to the simply aqueous ink for an ordinary fountain pens, the passage of said core rod of ink-guiding fibers will be soon blocked and the pen can not be used again. It is regretful to state that the signature pen with ball point has not embodied fully the advantages of both ball point pens and fountain pens.
Therefore, it is understood that the conventional writing instruments still have many unavoidable disadvantages. Some improvements are obviously need.